Self-propelling vehicle

ABSTRACT

The invention relates to a self-propelling vehicle which first, and possibly with the aid of a driver, drives along a selected route from a starting point to a destination, whereby the vehicle receives position signals from a positioning system and stores said signals in a data memory. The vehicle first receives an associated current position signal from the positioning system and at a point of departure when the vehicle subsequently and automatically drives along exactly the same selected route. Said signal is compared to the position of the starting point. If the positions do not match, the evaluation device calculates the direction towards and the distance to the starting point, whereupon the vehicle drives along this route. The direction and the distance to the next stored position are subsequently calculated using successively received current position data. The vehicle drives along the corresponding route. The vehicle can drive along a predetermined route inside a building when a local positioning system is used.

FIELD OF THE INVENTION

The present invention relates to a self-propelling vehicle which isequipped with a receiving and evaluating means for position signals, sothat it can constantly receive information about the coordinates of itsrespective location.

BACKGROUND OF THE INVENTION

EP-A-0 489 915 discloses a navigation system for the driver of anautomotive vehicle. Said navigation system is to improve the former mapdisplay system which creates safety problems, and the conventional arrowdisplay system which has the drawback that the driver often turns to theright or left too early from the road which is just being driven along.According to the disclosed invention the navigation system of theautomotive vehicle displays the route of travel through which thevehicle is just driving, together with information on the targetposition. Said traveling line is displayed on a screen.

EP 0 782 723 B1 discloses such a self-propelling vehicle which canautomatically follow a mobile transmitting means. The vehicle may be agolf caddy which follows a golf player who carries the mobiletransmitting means. Both the vehicle and the mobile transmitting meansare equipped with a receiving and evaluating means provided with acomputer for a satellite-controlled positioning system. The mobiletransmitting means transmits its respective position to the vehicle bymeans of a HF hand-held transmitter at regular time intervals, thevehicle comparing said position with its own position and calculatingthe traveling route therefrom.

SUMMARY OF THE INVENTION

The present invention does not deal with the problem that aself-propelling vehicle is to follow a mobile transmitting means alongits route, but the vehicle is to be able to drive exactly along one (orseveral) previously defined routes.

This problem is solved by the features of patent claim 1. Advantageousdevelopments of the invention are characterized in the dependent claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The system of the invention for controlling a self-propelling vehicleprovides as the first step that the position data of a selected routefrom a starting point to a destination are entered in the data memory.According to one embodiment the position data of the route to be drivenalong are directly entered or programmed without the route being drivenalong for such a purpose.

In another embodiment of the invention, said first step is as follows:the vehicle first drives along a selected route from a starting point toa destination, preferably with the help of a driver, with the vehiclereceiving position signals from a positioning system at preferablyregular time intervals of e.g. 1 s and storing said signals as a datasequence in a data memory. The vehicle has thus stored the coordinatesof route points located in any desired close way side by side.

For automatically following said programmed route, the vehicle receivesa current position signal which is compared by the computer of thevehicle with the programmed position of the starting point of thetraveling route. If the two positions do not match, direction anddistance from the starting point are calculated, whereupon the controlmeans of the vehicle becomes operative such that the vehicle travels tothe starting point.

The vehicle receives its respective current position data from thepositioning system at predetermined time intervals, the current positiondata being each compared with the next stored position of the travelingroute. Direction and distance to the next predetermined position arecalculated point for point, and the drive means and control unit areoperated such that the pre-programmed route is driven along.

Since the vehicle receives signals from the positioning system in ashort time sequence and the evaluating means calculates the respectivecurrent position of the vehicle from said signals, the vehicle canfollow the stored positions of the desired traveling route with highaccuracy because deviations from the desired route are immediatelydetected and corrected.

The positioning system whose signals are received by the vehicle may bea satellite navigation system such as GPS. Moreover, the systemaccording to the invention may include a stationary referencetransmitter which also transmits position signals to the vehicle, sothat the evaluating means thereof can correct the position data receivedfrom the satellite navigation system, whereby inaccuracies of theposition data of a satellite navigation system which are within therange of a few meters are corrected and the vehicle always calculatesits exact position coordinates.

With the system according to the invention, a transportation vehicle oralso a lawn mower, for example, can exactly follow a selected travelingroute at desired times without the help of an operator.

According to a further suggestion of the invention, the vehicle isequipped with sensors which can detect obstacles positioned along itspath. Said sensors may e.g. be microwave/ultrasonic and/or infraredtransmitters.

When an obstacle, such as an animal or a parked vehicle, is positionedalong the traveling route, the vehicle is preferably stopped and remainsin said inoperative position for a predetermined period of time and willonly continue its travel after the obstacle has been removed. If it isnot removed, the control means can guide the vehicle along a definedalternative path around the obstacle, and the traveling route to thenext stored route point positioned behind the obstacle is determined onthe basis of the next current position signal received.

New obstacles that appear are bypassed at a safety distance, while apracticable distance can be predetermined in the case of fixed obstaclespermanently positioned within the path.

If the vehicle determines its position with the help of a satellitenavigation system, it can drive along a predetermined route onlyoutdoors. The present invention suggests in this connection that insteadof a satellite navigation system a local positioning system can be usedthat covers a room such as a factory hall or salesroom e.g. with fourreference transmitters, thereby geographically defining every pointwithin said room. Within a building, e.g. four antennae transmit pulseswhich are evaluated by the receiving and evaluating means of the vehiclefor determining its respective coordinates in the room such as in thecase of a satellite navigation system. With such a local positioningsystem an industrial cleaning machine, for instance, can travel througha hall along a predetermined route, first with the help of a driver, theposition data of said route being stored in the memory of the machine,whereupon the cleaning machine will exactly follow the route without adriver being required.

Such a local positioning system with reference transmitters of its owncan also be used outdoors, for instance on a golf course or in a garden,so that a satellite navigation system can be dispensed with. The localpositioning system can also be used in cases where a vehicle is tofollow a movable transmitter automatically.

What is claimed is:
 1. A system for controlling a self-propellingvehicle comprising a positioning system for transmitting positionsignals and a self-propelling vehicle containing position signalreceiving means, position signal evaluating means, data memory storagemeans, and vehicle control means, characterized by the following steps:a) storing in the data memory the position data of a selected route froma starting point to a destination; b) causing said vehicle to followsaid selected route automatically in that b1) at a point of departure itreceives a current position signal from the positioning system andcompares said signal with the stored position of said starting pointand, if said position data do not match, calculates direction anddistance to said starting point therefrom and causes the vehicle totravel from said current position of departure to the starting point,and b2) then receives current position data in successive order andcalculates direction and distance to the next stored position and causesthe vehicle to drive along the selected route.
 2. The system accordingto claim 1, characterized in that in step a) the position data of theselected route are directly programmed.
 3. The system according to claim1, characterized in that in step a) a1) said vehicle is driven along aselected route from a starting point to a destination and a2) saidposition signal receiving means receives position signals from thepositioning system at time intervals and stores said signals in the datamemory.
 4. The controlling system according to claim 1, characterized inthat said positioning system is a satellite navigation system such asGPS.
 5. The controlling system according to claim 1, characterized inthat said receiving means receives position signals from a stationaryreference transmitter and determines its corrected exact position datatherefrom.
 6. The controlling system according to claim 1, characterizedin that said positioning system is a local positioning system.
 7. Thecontrolling system according to claim 6, characterized in that saidvehicle drives along said route within a building.
 8. The controllingsystem according to claim 1, characterized in that said vehicle detectsan obstacle along said route with the help of sensors.
 9. Thecontrolling system according to claim 8, characterized in that saidvehicle stops upon detection of an obstacle.
 10. The controlling systemaccording to claim 8, characterized in that said vehicle bypasses anobstacle in its way along a pre-programmed path.